35results about How to "Reduced oxidative weight gain" patented technology

The present invention discloses a Pt Ni Al bonding layer doped with binary trace active elements and capable of being completely oxidation resisting at 1200 DEG C and a preparation method thereof and belongs to the field of novel thermal barrier coatings and the preparation technologies. According to the invention, firstly, a Pt layer with the thickness of 5-10 microns is prepared on a nickel base monocrystal high temperature alloy matrix through the plating or the electron beam physical vapor deposition method, and then a NiAlHfZr coating with the thickness of 20-60 microns is deposited on the Pt layer through the electron beam physical vapor deposition method. The Pt layer reduces the interfacial holes and effectively improves the adhesion of an oxidation film; binary doping of Hf, Zr enables the NiAl coating surface to be smoother and denser and enables the oxidation film generated during the oxidation process on the coating surface to be straighter, especially with little oxidation increase, and greatly improves the oxidation resistance of the coating. The Pt Ni Al bonding layer is completely oxidation resisting at 1200 DEG C. The service life of the coating is prolonged to certain degree through doping of binary elements namely Hf and Zr and Pt modification.

The invention provides a titanium alloy laser surface silicide enhanced multielement high-temperature alloying layer. A titanium alloy Ti-6Al-4V serves as a base material, mixed powder composed of aluminite powder, niobium powder and silica powder serves as an alloying powder material to be arranged in the surface of the titanium alloy Ti-6Al-4V base material in advance, and a laser surface alloying technology is adopted for preparation, wherein the purity of the aluminite powder is higher than or equal to 99.0%, the grain diameter of the aluminite powder ranges from 50 microns to 100 microns, the purity of the niobium powder is higher than or equal to 99.5%, the grain diameter of the niobium powder ranges from 50 microns to 100 microns, the purity of the silica powder is higher than or equal to 99.5%, the grain diameter of the silica powder ranges from 50 microns to 100 microns; and the alloying powder material is prepared from, by weight, 100 parts of the aluminite powder, 10-20 parts of the niobium powder and 10-20 parts of the silica powder. The alloying layer is simple in composition proportion, the extremely-high hardness and the good high temperature frictional wear resistance are shown, and the excellent long-term high temperature oxidation resistance is achieved.

The invention discloses a titanium alloy composite capable of resisting high temperature oxidation and hot salt corrosion and a preparation method thereof. The titanium alloy composite comprises a titanium alloy substrate; a ceramic transition layer and an enamel coating are arranged on the surface of the titanium alloy substrate; the ceramic transition layer is located between the titanium alloysubstrate and the enamel coating; the ceramic transition layer is a micro-arc oxidation ceramic layer; and the enamel coating and the ceramic transition layer form a high-temperature protection gradient composite coating on the titanium alloy substrate. The titanium alloy composite is excellent in resistance to high temperature oxidation and high temperature hot salt corrosion and the gradient composite coating is good in chemical stability.

The invention discloses a method for improving long-term oxidation resistance of a high-niobium titanium-aluminum alloy through adding yttrium at high temperature, belonging to the high temperature oxidization field of the metal material. The invention is characterized in that Y is added in a Ti 45Aa17Nb alloy or a Ti 45Al 8Nb alloy, a tiny yttrium doping high-niobium titanium-aluminum alloy complete lamellar structure is obtained after using vacuum melting and homogenization treatments; the alloy comprises the following components by atomic percent: 46.4-47.9% of Ti, 45% of Al, 7-8% of Nb and 0.1-0.8% of Y; and the homogenization treatment process comprises the following steps: heat insulation is carried out at a temperature of 1320 DEG C for 12h, a converter is insulated for 30 minutes at a temperature of 900 DEG C and then taken out for air cooling. The invention has the advantages that adding proper amount of Y increases the proportion of Al2O3 in an oxide film, reduces the thickness of the oxide film, refines particles producing the oxide, facilitates plastic deformation of the oxide film and reduces cracking of the film; and by epoxidation experiments, after all alloys containing Y go through 1000 cycle periods, no obvious shedding phenomenon occurs in the oxide film, and addition of Y improves the adhesion of the alloy oxide film and raises the use temperature of the high-niobium titanium-aluminum alloy to the temperature of more than 900 DEG C.

The invention discloses a rhenium-containing hard alloy and a preparation method and application thereof. The rhenium-containing hard alloy is mainly prepared by mixing binder phase powder, Re powderand hard phase powder as raw materials, the mass fraction of the binder phase powder is 3-15%, the mass fraction of the Re powder is 5-30% of the mass fraction of the binder phase powder, the rest isthe hard phase powder, and Re in the rhenium-containing hard alloy is dissolved in the binder phase. The preparation method comprises the steps of proportioning, ball milling, drying granulation, molding and sintering of the raw materials according to a powder metallurgy method to obtain the rhenium-containing hard alloy, and the rhenium-containing hard alloy can be applied to preparation of hardalloy tools, especially milling and turning tools. The rhenium-containing hard alloy has high hardness, strength and fracture toughness, has good high-temperature oxidation resistance, and remarkablyprolongs the service life of a cutter.

The invention relates to a grid section used for sintering acid mine. The grid section comprises the following components in percentage by weight: 1.1-1.3% of C, 26.0-28.0% of Cr, 0.3-0.5% of Mo, 1.0-1.5% of Ni, 1.0-1.5% of Si, 0.5-1.0% of Mn, 0.10% of Ti, 0.05-0.15% of Re, 1.0-2.0% of Al and the balance of Fe. The grid section disclosed by the invention is totally suitable for acid mine sintering working conditions and satisfies use requirements, the service life of the grid section is prolonged to more than 12 months from less than 3 months, and therefore the use cost of the grid section isgreatly lowered. Meanwhile, replacement frequency of the grid section can be reduced, the labor intensity of operators is lowered, downtime for replacing the grid section is shortened, and productionefficiency is improved.

The invention relates to a double-layer Cr/Cr2AlC coating for an accident fault-tolerant fuel cladding and a preparation method of the double-layer Cr/Cr2AlC coating. The protection capacity of the zirconium alloy cladding under the normal operation working condition and the accident working condition can be effectively improved by coating the surface of zirconium alloy with the double-layer coating. The double-layer Cr/Cr2AlC coating is deposited on the surface of the zirconium alloy by adopting a multi-target magnetron sputtering technology, the bonding between the coating layers and between the coating layers and a matrix is good, the total thickness is 4-10 microns, and the thickness range of the Cr2AlC coating is 3-8 microns. The double-layer coating integrates the advantages of the two coatings, and the Cr coating not only effectively relieves thermal stress between the coating and a zirconium alloy matrix, but also has the accident fault tolerance capability; the Cr2AlC coating not only has good oxidation resistance in a high-temperature water vapor environment, but also shows excellent fretting wear resistance in a high-temperature and high-pressure water environment under a normal operation condition of a reactor, and protects the zirconium alloy matrix from being oxidized in a high-temperature and high-pressure water corrosion process, and reliability and safety of operation of a nuclear fuel system can be obviously improved.

The invention discloses a high-density nano W alloy with good self-passivation behavior and a preparation method thereof. The nano W alloy is prepared from the components in percentage by weight: a basic component W, a passivation element Cr and activation elements Y and Zr, wherein Cr is greater than or equal to 10wt.% and less than or equal to 13wt.%, the total amount of the activation elementsis greater than 0wt.% and less than or equal to 2wt.%, and the balance is W. By controlling process parameters such as the sintering temperature and pressure, the heating rate and the heat preservation time during sintering, the high-density nano W alloy is obtained. The W alloy with the relative density being higher than 98.5% and the grain size being less than 100 nm is obtained under the conditions that the sintering temperature is 1150 DEG C and the applied load is 90 MPa. The nano W-alloy shows the good self-passivation behavior, and the oxidation weight gain of the nano W-alloy is only 7.8 mg/cm<2> after 165 h of heat-shock oxidation under the air atmosphere of 1000 DEG C.

The invention belongs to the technical field of inorganic non-metallic materials, and particularly relates to an AlON ceramic composite material and a preparation method thereof. According to the invention, AlON, SiC and B4C powder are used as raw materials, and the AlON composite ceramic material is prepared by a hot pressed sintering method by adjusting the mass ratio of SiC to B4C. After the obtained product is statically oxidized for 40 hours in air at 1500 DEG C, the oxidation weight gain rate is reduced by 78.8%-85.7% compared with that of pure AlON ceramic, the bending strength at room temperature is 301-324 MPa, the fracture toughness is 1.40-1.51 MPa.m<1/2>, the oxidation resistance of the AlON material is greatly improved, and a reference is provided for further application of the AlON ceramic in the high-temperature field.

The invention relates to a SiO2-mullite-Al2O3 multi-component gradient anti-oxidation coating and a preparation method thereof. The preparation method comprises the following steps: firstly, mechanically grinding a titanium alloy matrix, and then carrying out polishing treatment and ultrasonic cleaning; the cleaned titanium alloy matrix is dried in an air dry oven; plating a Si elementary substance layer on the surface of the titanium alloy by adopting a direct current sputtering mode on the dried substrate; carrying out oxidation treatment on the Si-plated substrate at a high temperature; taking out the titanium alloy substrate, and uniformly laying a layer of aluminum foil on the surface; placing the titanium alloy substrate in a vacuum furnace, preserving heat at high temperature to completely melt the titanium alloy substrate, and uniformly coating the titanium alloy substrate on the surface of the titanium alloy substrate; a titanium alloy substrate is subjected to oxidation treatment in air to obtain SiO2 and Al2O3, a mullite phase is generated through the reaction between the SiO2 and the Al2O3, and the SiO2-mullite-Al2O3 multi-component gradient anti-oxidation coating is obtained. According to the method, the oxidation resistance of the titanium alloy matrix can be improved.